Door frame and roll-up door mechanism for air locks



3,006,352 DOOR FRAME AND ROLL-UP DOOR MECHANISM FOR AIR LOCKS Filed Nov. 27, 1959 R. F. HOZAK Oct. 31, 1961 5 Sheets-Sheet 1 INVENTOR ATTORNEY lll.) III II llllllllll...

R. F. HOZAK Oct. 31, 1961 DOOR FRAME AND ROLL-UP DOOR MECHANISM FOR AIR LOCKS Filed NOV. 27. 1959 5 Sheets-Sheet 2 INVENTOR mam; A wZA /r,

ATTORNE 31, 1961 R. F. HOZAK 3,006,352

DOOR FRAME AND ROLL-UP DOOR MECHANISM FOR AIR LOCKS Filed Nov. 27. 1959 5 Sheets-Sheet 3 R. F. HOZAK Oct. 31, 1961 DOOR FRAME AND ROLL-UP DOOR MECHANISM FOR AIR LOCKS Filed NOV. 27, 1959 5 Sheets-Sheet 4 ATTORNEY Oct. 31, 1961 R. F. HOZAK 3,006,352

DOOR FRAME AND ROLL-UP DOOR MECHANISM FOR AIR LOCKS Filed Nov. 27, 1959 5 Sheets-Sheet 5 J31 2;} 5 M. TE 1 ,3

I 774 INVENTOR I BY ATTORNEY United States Patent 3,006,352 DOOR FRAME AND ROLL-UP DOOR MECHANISM FOR AIR LOCKS Robert Frank Hozak, Chicago, Ill., assignor to Cid Air Structures Company, Chicago, 11]., a corporation of Illinois Filed Nov. 27, 1959, Ser. No. 855,703 6 Claims. (Cl. 1351) My invention relates broadly to air locks for air pressure supported structures and the like, and more particularly to a construction of air lock having roll-up doors constructed of a flexible material and selectively operable through a motor drive system.

One of the objects of my invention is to provide a construction of air lock having a pair of roll-up flexible awning type doors in which the seal between the doors and the door frame is maintained by the air pressure within the structure.

Another object of my invention is to provide a simple construction of air lock for air pressure supported structures in which the air lock supporting frames are pivotally connected to anchoring plates to facilitate fast and easy erection thereof.

Another object of my invention is to provide a simple construction of motor operated roll-up awning type doors for air locks in which the doors are closed by gravity action.

Still another object of my invention is to provide a construction of gripper mechanism for controlling the gravity closing of the roll-up doors of the air lock of my invention.

A further object of my invention is to provide a simple and efficient construction \of seal for joining the air lock of my invention to the fabric body of the main air supported structure.

Other and further objects of my invention reside in the simple construction of the air lock and door frames thereof as set forth more fully in the specification hereinafter following by reference to the accompanying drawings, in which:

FIG. 1 is a front elevational view showing the roll-up door air lock of my invention attached to an air pressure supported structure;

FIG. 2 is a side elevation view of the air lock and air supported structure shown in FIG. 1;

FIG. 3 is a longitudinal sectional View through the roll-up door air lock of my invention taken substantially on line 33 of FIG. 1, and particularly showing the roll-up door control system;

FIG. 4 is a cross-sectional view taken substantially on line 4-4 of FIG. 3 and particularly showing the construction of an intermediate air lock arch;

FIG. 5 is a cross-sectional view taken substantially on line 5-5 of FIG. 3 and particularly showing the door frame construction and arrangement of the roll-up door and drive mechanism assembled thereon;

FIG. 6 is an enlarged view partly in cut-away section of a fragmentary portion of FIG. 4, particularly showing the manner in which an intermediate arch is pivotally connected to its base plate and the manner in which the air lock skin is sealed to the ground;

FIG. 7 is a horizontal sectional view taken substantially on line 77 of FIG. 6;

FIG. 8 is an enlarged view of a fragmentary portion of FIG. 5, partly in cut-away section, to show the manner in which the door frame is pivoted on its base plate and the manner in which the air lock skin is secured to the door frame;

FIG. 9 is a cross-sectional view taken substantially on line 99 of FIG. 5;

FIG. 10 is an enlarged sectional view of a fragmentary 3,006,352 Patented Oct. 31, 1961 portion of FIG. 3 and particularly showing the manner in which the lock is sealed to the main air structure;

FIG. 11 is an enlarged elevational view of a fragmentary portion of FIG. 5 showing the arrangement of motor drive assembly and belt drive gripper for the roll-up door;

FIG. 12 is a partial side elevation view of the roll-up door motor drive assembly and particularly showing in cut-away section the belt gripper mechanism in the normal and locked position;

FIG. 13 is a side elevation view similar to FIG. 12 but showing the belt gripper mechanism in the unlocked position;

FIG. 14 is a cross-sectional view taken on line 1414 of FIG. 11 and showing a top plan view of the belt gripper mechanism in the unlocked position corresponding to FIG. 13; I

FIG. 15 is a fragmentary vertical sectional view showing the roll-up air lock door of my invention in a partly rolled up position; and

FIG. 16 is a fragmentary elevational view of a. modified form of roll-up door motor drive assembly.

My invention is directed to the construction of an air lock having end door frames and roll-up doors for air pressure supported structures. The air lock consists of a flexible covering, through which air cannot escape, supported by arcuate-shaped end frames and arcuate-shaped intermediate support arches. The fabric provides ties on the inner surface for attachment to the intermediate arches and is coupled to the end channel frames by a cable in tension secured to the end frames and extending through a hem in the end of the fabric. The air lock is coupled to the main air supported structure in the same manner except that the tensioned cable extends through an arcuate hem provided on the side Wall of the air structure. Each end frame and intermediate arch is pivotally connected to an anchored base plate, thus permitting the end frame and arches to be installed when the air structure is on the ground and then pivoted to the upright position as the structure is inflated.

Each end frame carries a roll-up door of flexible material which is reinforced at regular intervals by rods running horizontally therethrough to prevent the air pressure from buckling the door and to provide a relatively tight air seal between the end frame and the roll-up door. The air seal is provided by the weight of the rods and by the air pressure pushing out on the door thus pushing it into abutment with the end frame.

A motor drive mechanism is provided above each door driving a shaft by means of a belt and pulley arrangement. The shaft is arranged to wind a pair of control lines thereon which are passed around the roll-up door such that as the lines are wound onto the shaft the door is rolled up in awning fashion. The shaft is connected to the end frame by means of bearing members.

A gripper mechanism through which the shaft drive belt passes is arranged to grip the drive belt in a manner so as to prevent the door from rolling back down from the elevated position whenever the motor stops. Lines connected 'to a control arm on the gripper mechanism enable the belt to be selectively released thus permitting the roll-up door to close by gravitational force.

Thus by means of strategically placed electric switches which elevate the roll-up doors and door release lines which close the doors, a person passing through the air lock can first elevate one door, pass into the air lock, close the samedoor, then elevate the second door, pass out of the air lock into the main air structure, and then close the second door without any substantial lose of air pressure in the main air structure.

Referring to the drawings in more detail the roll-up door air lock of my invention in indicated generally at 1 I joined to the air supported structure shown at 2. The

air lock frame consists of end channel frames 3 and 4, and intermediate supporting arches 5 to which the air lock flexible fabric skin 6 is secured at regular intervals by the tie members shown at 7 secured to the interior surface of the fabric skin. A Y

Each intermediate supporting arch 5 is of identical constructionand consists of a tubular member or the like formed to the same radius as the end channel frames 3 and 4, and spaced at regular intervals to support the air airlock fabric covering 6 when the air pressure in the air lock is substantially the same as the air pressure exterior of the air lock, that is, to support the fabric skin when the interior roll-up door of the air lock is closed. I have found that placing the intermediate support arches 5 approximately every eight feet along the length of an air lock provides eflicient and effective support thereto. The terminating ends of the intermediate arches are each pivoted on an anchor base plate 8 by means of an angularly formed'pintle 9 having one portion thereof welded to the arch terminating end and the other end thereof extending into pivoted engagement with a pivot bearing member 10 secured to the base plate 8. Each base plate 8, as particularly shown in FIGS. 6 and 7, is secured to the ground indicated at 11 by stakes 12 driven through holes provided in the four corners of the base plate.

The bottom terminating edge of the air lock flexible skin 6 is providedwith grommets 13 therethrough at regular intervals adjacent the edge thereof. The terminatingedge is then secured flush to the ground 11 by stakes 14 driven through the grommets. The stakes 14 are driven through the grommets 13 from the interior side of the air lock thus pulling the terminating edge of the skin slightly inside the air lock and providing an effective anchor for the terminating edge which counteracts the outward and upward pull of the flexible skin caused by increased interior pressure when the inner air lock door is opened into the associated air supported structure 2.

The air lock end channel frames 3 and 4 are of similar construction and are assembled onto the air lock in a similar manner at similar acute angles with the verticalaxis, except that the frames lean in opposite directions away .from each other. The frames are also disposed. to face in in the same direction. End frame 3 carries the outer air lock door 15 while end frame 14 carries inner air lock door 15'. The air lock is joined to the air supported structure 2 by means of end frame 4. Since the side walls of the air supported. structure extend at acute angles to. the vertical axis this causes the end frame 4 to lean at the same acute angle with respect to the vertical axis. The degree of lean is governed by the relation of the size of the air supported structure and the size of the air lock fitted to the structure. End frame 3 is disposed to counteract the leaning of .end frame 4 by leaning in the opposite direction at the same degree of lean. of end frame 3 are provided with trunbuckles 17 protruding therefrom which maintain the intermediate arches.

5 through the flexible covering 6, and end channel frames 3 and 4 in their proper erected positions by maintaining tension on anchored cables 18 connected to the. other ends thereof.

The end frames 3 and 4 are substantially identicalin construction and to avoid duplication of description the construction of only end frame 3 will be discussed in detail, but corresponding similar parts on, end frame 4 have been shown indicated in prime numbers correspondingto the parts indicated by the non-prime numbers, on end,

frame 3. Endframe 3 consists of three segments joined together by gusset plates thereto at the welded junction of the vertical-door frame.

Gusset plates 16 on the exterior side.

16. The two side frame seg-, ments each consists of a vertical door frame member 19 nilmember 19 and curved channel segment 20. One portion of the pintle extends outwardly beneath the frame structure into pivotal engagement with a pivot bearing 23 carried by a base plate 24 anchored to the ground 11 by stakes 25 through the four corners of the base plate. This pivot mounting provides degrees of pivotal movement to the end frame member with respect to the ground and adds to the ease of erecting the air lock structure, since in the erection process the frames and intermediate arches are installed when the air supported structure is on the ground and then are pivoted into an upright position as the structure is inflated.

The top segment of end frame 3 consists of horizontal door frame member 26 connected to the curved channel segment 27 by cross members 28 and motor assembly mounting channel 29 centrally carried thereon. The terminating ends of channel 27 and horizontal door frame member 26 are bolted to the gusset plates 16 to form the assembled end frame 3.

Fabric panels shown at 30 and 31 are laced to the interior sides of the side frame segments and top frame segment, respectively, the lacing securing the panels to the door frame members 19 and 26. The outer edges of panels 30 and 31 extend into the channel segments 20 and 27 and are secured therein by the tensioned cable 32 in the terminating hem 33 of the flexible fabric air lock covering 6 as shown in FIG. 9.

Each end of the air lock flexible covering 6 adjacent the end support frames terminates in a reinforced hem shown at 33 through which is threaded a fabric covered cable 32 preferably of the wire rope type for securing the flexible covering 6 to the end support frames 3 and 4. A threaded bolt and eye takeup assembly, shown at 34, is secured inside the outer channel segments 20 and 20 of the end frames 3 and 4, respectively, adjacent the pivot mountings on the bottom extremities of the end frames. The cable-bearing hem 33 is disposed in the outer channel of the end frames and with the ends of the cable 32- secured to the eye members of the bolt and eye takeup assemblies 34 on either side of the respective frames, the takeup assemblies are tightened so as to putthe cables 32 in a state of tension Within the channel members of the frame and thus securing the flexible skin 6 at either end thereof to the end frames 3 and 4.

The main air supported structure 2 is secu red to the air lock in a like manner. The side wall of the air supported structure 2 carries a reinforced arcuate hem 35 carrying fabric covered cable 36 which is connected at either end thereof to the bolt and eye takeup assemblies 34 of end frame 4, in the same manner in which cable 32 is connect-ed thereto. As the bolt and eye assemblies are tightened the hem 35 of the main air structure is tightly sealed in the outer channel of end frame 4 by the tensioned cable 36, thus sealing the air lock 1 to the main air structure 2, as more particularly shown in FIGS. 3 and 10.

The fabric panels 30' and 31' corresponding to fabric panels 30 and 31 are sewed at the outer edges thereof to the arcuate hem 35 of the main air supported strucframe members 19 and 26 in the same mannerin which panels 30 and 31 are secured to their respective door frame members.

7 Outer air lock roll-up door 15 and inner air lock rollup door 15 are constructed of the same type flexible fabric asthe air lock skin 6, the preferred fabric being 16 ounce vinyl-coated nylon. Each roll-up door carries a clear flexible plastic window shown at 37 for greater convenience. At regular intervals along the vertical dimension of each door and extending horizontally across the width of thedoor I provide sleeves or pockets shown at 38 sewed to the door panel fabric which carry walltubes 39 for adding weight tothe roll-updoors, thus allowing them to roll down by gravitationalzforce from.

therolled up position. They also prevent the doors from buckling under the air pressure applied thereto, thus insuring a relatively tight seal between the roll-up door and the door frame when the door is in the closed position. Roll-up door 15 is fastened to the interior air lock side of end flame 3 while roll-up door 15 is fastened to the main air structure side of end frame 4. With this arrangement the air structure air pressure always presses the roll-up doors flush against their respective door frames thus creating a relatively tight seal therebetween due to the air pressure action. The roll-up doors are hung on the horizontal door frame members 26 and 26 by means of bolts, shown at 40, threaded therein.

The roll-up door motor drive assembly is mouned above the door on the end frame member and is mounted on the same side of the air lock end frame as the rll-up door. The door drive assembly comprises an electric motor 41, mounted on motor assembly mounting channel 29 through the fabric panel 31, disposed to drive belt 42 by means of pulley 43. The other end of the closed loop belt 42 is engaged by pulley 44 keyed to the horizontally disposed shaft 45 which is rotatively mounted to the cross members 28 and motor assembly mounting channel 29 of the end support frame by means of pillow block bearings 46. Control ropes 47 and 48 are secured to shaft 45 adjacent the center pillow block bearing 46 and pulley 44 secured thereto. The control ropes 47 and 48 extend from shaft 45 at acute angles down the interior face of the door, under the bottom of the door, up the outer face of the door and terminate anchored to the top door frame member 26 adjacent the ends of shaft 45. When the motor 41 is energized the belt 42 is rotated in a counterclockwise direction as shown in FIG. 12, thus rotatively driving shaft 45 causing control ropes 47 and 48 to be gathered onto the shaft in a single layer, because of the angular relation between the control ropes and the shaft, thus causing the door 15 to roll-up as shown in FIG. 15, due to the action of the control ropes.

The motor is deenergized when the roll-up door 15 reaches the top of its travel and is prevented from rolling back down by a gripper mechanism shown at 49 which I provide to coact with belt 42. The gripper mechanism 49 comprises a support member 50 welded to motor assembly support channel 29, the support member 50 having a depending arm 51 bent back upon the support member but in spaced relation thereto, as shown in FIG. 14. A shaft 52 is journaled between support member 50 and depending arm 51, the shaft 52 carrying a circular belt gripper member 53 welded thereto. Shaft 52 extends through support member 50 and terminates in a rigidly connected control arm 54 having door release lines 55 and 56 connected to either end thereof. An L-shaped bottom plate 57 is secured to support member 50 opposite de pending arm 51 such that the belt gripper member 53 is disposed therebetween but biased in the direction of bottom plate 57 by the weight 58 on the bottom portion of control arm 54. Bottom plate 57 is L-shaped to retain the belt in the gripper mechanism. Drive belt 42 is disposed through the gripper mechanism between the bottom plate 57 and the belt gripper member 53, such that, in the normal position, weight 58 rotates belt gripper member 53 into abutment with belt 42 so as to securely grip the belt between the bottom plate 57, which is disposed parallel with the belt, and the gripper member 53, thus preventing any clockwise rotation of belt 42. Thus as the door 15 is being rolled up the direction of belt travel, as shown in FIG. 12, prevents the gripper mechanism from gripping the belt, but when the motor is stopped the belt is tightly gripped and prevented from rotating in the opposite or clockwise direction and thus the door 15 is prevented from rolling back down from the rolled up position.

Control arm 54 is a lever arm for belt gripper member 53; thus by pulling either of the door release lines 55 or 56 the belt gripper member 53 is rotated counterclockwise out of engagement with belt 42. With belt 42 in the released state, the weight of the rolled up door returns the roll-up door to the closed position by gravitational action. While the door is rolling down to the closed position the control ropes 47 and 48 rotate shaft 45 such as to rotate belt 42 in a clockwise direction. FIGS. 13 and 14 show the gripper mechanism in the unlocked state.

As shown in FIG. 3, door release lines 55 and 56' extend into the interior of the air lock along with motor control switches 59 and 60' for starting and stopping motors 41 and 41', respectively. The door release lines and motor control switches are all mounted together in a conveniently accessible spot, preferably in the center of the air lock. The motor control switch 60 which is disposed in electrical parallel with control switch 59 for controlling the excitation to motor 41 is disposed in a convenient location outside the air lock with door release line 56 close at hand. Release line 56 extends through the fabric panel 31 from the interior of the air lock and then extends exterior of the air lock to a position near the switch 60 for closing the roll-up door from outside the air lock. In like manner switch 59' and release line 55 extend to a convenient control point within the main air structure 2 for controlling roll-up door 15'.

The following is the procedure used by a person entering the main air supported structure 2 by way of the air lock 1. First, the person at'position No. 1 reaches for switch 60 and holds it depressed while roll-up door 15 elevates to the rolled up position. Second, the person advances into the air look to position No. 2 and pulls door release line 55 permitting roll-up door 15 to roll down to the closed position. Third, the person at the same position depresses electrical control switch 60' and holds it in the depressed position while motor 41' elevates roll-up door 15'. Fourth, the person advances to position No. 3, inside the main air structure 2, and pulls down release line 55' thus permitting roll-up door 15' to roll down by gravitational force to the closed position, thus completing the trip through the air look. When a person wishes to pass through the air lock from the main air structure end the reverse procedure is used, but utilizing switch 59', door release line 56', switch 59, and door release line 56, in that sequence.

I have shown a modified form of roll-up door motor drive assembly in FIG. 16. In this modified arrangement I have shown an electric motor indicated at 61 coupled directly to the end of roll-up shaft 62 for rotating same in order to roll-up the door, indicated at 63, by means of lines 64 and 65 being wound onto said shaft. As in the principal form of my invention the shaft 62 is supported on the end frame by means of pillow block bearings shown at 66. Shaft 62 carries a ratchet wheel 67 secured thereto which coacts with pawl 68 to prevent the roll-up door 63 from rolling back down from the elevated position. Door release line 69 having a portion running to a position on each side of the door is connected to pawl 68 and arranged to lift the pawl out of engagement with the ratchet wheel when the line is pulled to allow the door to drop or roll down to the closed position by gravitational force. I have found that a HR, volt, 1725 rpm. motor is best adapted to till the requirement of the roll-up door motor drive mechanism in both forms of my invention.

I have constructed and have extensively tested the air lock and roll-up door mechanism of my invention and have found it eflicient, reliable, and very convenient to use. It is especially valuable for providing large openings into air supported structures through which trucks or large vehicles may pass.

While I have described my invention in certain preferred embodiments I realize that modifications can be made and I desire that it be understood that no limitations upon my invention are intended other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A collapsible air lock for flexible air-pressure sup ported building structures comprising a pair of upstanding frame members disposed in aligned spaced relation and pivotally mounted at their bases to allow said frame members to raise to an elevated position as the air-pressure supported building is elevated, one of said frame members secured in a side wall opening of the building structure, a door frame having a horizontal top member defined by each of said upstanding frame members, an air impermeable fabric covering secured to the perimeter of the upstanding frame members and extending therebetween to form a passage-like structure, an air impermeable fabric door panel secured to the horizontal top member of each door frame, said door panels covering the openings formed by said door frames, a control shaft rotatably mounted to the upstanding frame members above each door panel, motor means for selectively rotating said shafts, and control lines connecting said door panels and the rotatable control shafts for rolling up said fabric door panels when the motor means are energized.

2. A collapsible air lock for flexible air-supported building structures as set forth in claim 1 including intermediate upstanding support frame members, said members being connected to said air impermeable fabric covering, and said members being pivotally mounted at their bases to allow said support members to raise to an elevated position as the air-pressure supported building is elevated.

3. A collapsible air lock for flexible air-pressure supported building structures comprising a pair of arcuateshaped end support members disposed in aligned spaced relation and pivotally mounted at their bases to allow said support members to raise to. an elevated position as the air-pressure supported building is elevated, one of said support members secured in a side Wall opening of'the building structure, a. generally square door frame having a horizontal top member carried by each of said end support members, an air impermeable fabric covering secured to the perimeter of the arcuate end support members and extending therebetween to form an arcuate tunnel-like structure, air impermeable fabric panels: secured intermediate the arcuate-shaped end support members and: the door frame carried thereby, an air impermeable fabric door panel secured to the horizontal top. member. of each door frame, said door. panels disposed on the high, pressure side of said door frames and covering the openings formed by said door frames, a control' shaft rotatably mounted to the end support members above each door panel, motor means for selectively rotating said shafts and control lines connecting said doorpanels and the rotatable control shafts for rolling up said fabric door panelswhen the motor means are energized.

4.. A collapsible.-

lock for flexible air-pressure sup ported building structures. as set forth in' claim 3 in which said air impermeable fabric door panels partly overlie the fabric panels secured intermediate the arcuate-shaped end; support members and the door frames, and are held in abutting relation therewith by the increased air-pressure when the; doors are in. the closed position to provide an effective air lock door seal;

5. A collapsible a'ir lock for flexible air-pressure supportedbuildin'g structures as set forth in claim 1 including tie means connected interiorly of said air impermeable fabric covering intermediate said upstanding frame members, and intermediate upstanding support frame members pivoted at their bases disposed between said first mentioned upstanding frame members and connected to said air impermeable fabric covering by said tie means to provide a supported collapsible air lock of any desired length.

6. In an air lock for flexible air-pressure supported building structures containing pressure greater than the atmosphere; an upstanding support frame defining a door opening, a horizontal member defining the top of the door opening connected to said upstanding support frame, said upstanding support frame being pivotally mounted atthe base thereof to allow said support frame to raise to an elevated position as the air-pressure supported building structure is elevated, an air impermeable fabric door panel. connected to said horizontal member on the high pressure side of the support frame, said fabric door panel covering the door opening defined by said upstanding support frame and being disposed in overlying abutting relation with the edges of the door opening, horizontally disposed reinforcing elements carried by said fabric door panel, a. horizontal shaft journaled for rotative movementto. saidsupport frameabove said fabric door panel, control lines connecting said shaft and said fabric door panel, motor means, a drive belt connecting said motor means to said shaft for imparting selective rotative movement thereto for rolling. up said fabric door panel, and a gravity-operated belt gripping element having a pivotally mounted releasable belt gripping counterweight for automatically gripping, said drive belt to maintain said fabric door panel'in the rolled up position.

References Cited in the file of this patent UNITED STATES PATENTS 1,302,182 Lanchester Apr. 29, 1919 2,355,248 Stevens Aug. 8, 1944 2 ,513,152 Delivuk June 27, 1950 2,631,661 Nelson Mar. 17, 1953 2,827,138 Roy Mar. 18, 1958 2,914,776 Hotz Dec. 1, 1959 

